ES2376018T3 - UNIDIRECTIONAL CLUTCH OF ROLLER TYPE. - Google Patents

Abstract

The present invention provides a roller type one-way clutch comprising an outer race in which pockets provided at their inner surfaces with cam surfaces are formed, an inner race spaced apart from the outer race in a radial inner diameter side and disposed coaxially with the outer race for a relative rotational movement and having an annular outer peripheral track surface, a roller disposed within the pocket to be engaged with the cam surfaces and adapted to transmit torque between the outer race and the inner race, and an accordion spring disposed within the pocket and adapted to bias the rollers to be engaged with the cam surfaces, and wherein one end of each accordion spring is secured to an axial end face of the outer race.

Description

Unidirectional roller type clutch

5 TECHNICAL SECTOR

The present invention relates to a unidirectional roller-type clutch, used as a part such as a torque transmission element or a recoil stop in a driving apparatus of a car, an industrial machine or the like, for example .

10 BACKGROUND OF THE TECHNIQUE

In general, a unidirectional roller type clutch is constituted by an outer race, an inner race coaxially arranged with the outer race, a series of rollers arranged between an outer peripheral surface

15 of the inner race and an inner peripheral cam surface of the outer race and adapted to transmit pairs of forces, and springs that contact the rollers on a free rotating side.

With this arrangement, in the unidirectional clutch, the inner race is rotated only in one direction with respect to the outer race by a cam mechanism constituted by the rollers and the cam surface. Is

In other words, the inner race is designed so that the inner race is rotated freely with respect to the outer race, in one direction, and serves to transmit rotary torque to the outer race by the cam mechanism, only in the opposite direction .

In general, in the unidirectional clutch of roller type, to achieve effective coupling, the rollers,

25 as transmission elements of pairs of forces and the springs for deflecting the rollers are arranged in respective cavities formed in the outer race or in the inner race.

Particularly, in a unidirectional roller-type clutch for a motorcycle, since the number of rollers is small (for example, three or six), if all the rollers are not coupled with the cam surfaces

30 correspondingly, the capacity of design force pairs cannot be achieved. In this way, it is important that the springs to deflect the rollers are operated stably.

Japanese patent application for public inspection number 2003-172377 discloses a technique in which parts of a cage are arranged in cavities to prevent the rollers and springs from being evicted

35 towards an inner peripheral side of the outer race. However, this document does not disclose the fact that the springs are fixed to the outer race.

If the accordion springs are simply retained with respect to the outer race, the relative positions between the accordion springs and the outer race cannot be determined or stabilized, with the result that when

40 the springs are in sliding contact with a part of the inner diameter of the outer race, a part of the outer diameter of a cage or a guide surface of the inner race, the springs can be worn or damaged by wear. In addition, in that case the problem arises that, in operation, the movements of the springs cannot be stabilized, with the result that it is difficult to achieve smooth movements.

45 DESCRIPTION OF THE INVENTION

Accordingly, an objective of the present invention is to disclose a unidirectional roller-type clutch in which fluctuation in relative positions between the accordion springs and an outer race is eliminated, so that said accordion springs are not in sliding contact with a part of the diameter

50 inside the outer race, a part of the outer diameter of a cage or a guide surface of an inner race, thus preventing the springs from wear and / or damage due to wear, and in which the movements of said springs Accordion are stabilized during operation.

To achieve the above objective, the present invention discloses a unidirectional clutch of the type of

55 rollers, comprising an outer race in which cavities formed on their inner surfaces of cam surfaces are formed, an inner race separated from the outer race on a radial inner diameter side and coaxially arranged with the outer race for rotational movement relative and having an annular outer peripheral guide surface, a roller disposed within each of the cavities in order to engage with cam surfaces and adapted to transmit pairs of forces between the outer race and the inner race, and a spring

60 in accordion arranged within each of the cavities and adapted to deflect the rollers in order to engage with the cam surfaces, and in which one end of each of the accordion springs is fixed to an axial end face of the outer track.

In addition, each of the accordion springs can be curved in an axial direction. 65

In addition, the end of each of the accordion springs can be fixed to the axial end face of the outer race by welding.

In addition, the end of each of the accordion springs can be fixed to the axial end face of the outer race by spot welding.

The end of each of the accordion springs can be fixed to the axial end face of the outer race by means of an adhesive.

The end of each of the accordion springs can be fixed to the axial end face of the outer race by welding alloy.

The unidirectional roller-type clutch can include a cage that has a cylindrical part and a flange part that extends from the cylindrical part towards an outside diameter direction and that has windows formed in the cylindrical part and adapted to contain the series of rollers, and the flange part that extends towards the direction of the outer diameter is formed on an axial end part of the cylindrical part.

An inner peripheral surface of the outer race may be provided at its axial edge with an annular stepped portion with which the flange portion of the cage is coupled.

Thanks to the unidirectional roller type clutch of the present invention, the following effects can be achieved.

With the arrangement in which the accordion spring is fixed to the outer race, since the relative position between the accordion spring and the outer race does not fluctuate, it is possible to prevent wear and / or breakdown of the spring due to the sliding contact between the spring and the inner diameter part of the outer race, the outer diameter part of the cage or the guide surface of the inner race.

In addition, since the operating movement of the spring is not influenced by the outer race and the cage, stable and uniform movement can be achieved. As a result, the coupling capacity of the roller is improved.

With the arrangement in which the inner peripheral surface of the outer race is provided at its axial edge with the annular stepped part with which the flange portion of the cage is coupled, since it is not necessary to reduce the axial length of the track outside in a magnitude corresponding to the thickness of the flange part, the axial length of the outer race can be preserved.

In addition, since the rollers and springs can be prevented from being dislodged in the axial and radial directions, said rollers can be effectively coupled even under an environmental condition in which many vibrations would be generated, for example, on a motorcycle and Similary.

The additional features of the present invention will be apparent from the following description of exemplary embodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a front view of a unidirectional roller type clutch, according to a first embodiment of the present invention, showing a state prior to the clutch being engaged;

Figure 2 is an axial section view of Figure 1;

Figure 3 is a front view of a unidirectional roller type clutch, according to a second embodiment of the present invention, showing a state prior to the clutch being engaged;

Figure 4 is a front view showing the unidirectional roller type clutch, according to the second embodiment of the present invention;

Figure 5 is a front view from a side posterior to that of Figure 4;

Figure 6 is a view, in axial section, along the line -B-B- in Figure 5;

Figure 7 is a front, partial view of the unidirectional roller type clutch before an inner race is mounted;

Figure 8 is a side view, partial, from one side of the inner diameter of Figure 7;

Figure 9 is a partial front view for explaining the operation of the unidirectional roller-type clutch, in a state in which the inner race is freely rotated;

Figure 10 is a partial front view for explaining the operation of the unidirectional roller-type clutch, in a state in which the inner race is displaced from free rotation to a rotation in the opposite direction; Y

Figure 11 is a partial front view to explain the operation of the unidirectional roller type clutch, in a state in which the inner race is rotated in the opposite direction.

BEST MODES OF CARRYING OUT THE INVENTION

Next, embodiments of the present invention will be fully explained with reference to the accompanying drawings. In this regard, it should be noted that the embodiments described below are simply examples of the present invention and various changes can be made therein.

(First realization)

Figure 1 is a front view of a unidirectional roller-type clutch, according to a first embodiment of the present invention, and Figure 2 is a view, in axial section, of Figure 1. In Figure 2, a -2-interior track through a dashed line.

Figures 1 and 2 show a state prior to the rollers being engaged, that is, an unlocked or free-rotating state of the unidirectional clutch. In the embodiment shown, the inner race -2 is freely rotated.

As shown in Figure 1, a unidirectional roller-type clutch -30- comprises an annular outer race -1- provided on its inner periphery with cavities -4- formed as recessed parts having cam surfaces -12-, an inner track -2- (shown by a dashed line in figure 2) separated from the outer track -1- radially inwards and arranged coaxially with the outer track for relative rotational movement and having a peripheral guide surface outer ring -11-, and a series of rollers -3- arranged within the corresponding cavities -4- and adapted to transmit pairs of forces between the outer peripheral guide surface -11-of the inner race -2- and the surfaces of cam -12-.

In the embodiment shown, three cavities -4- are arranged on the inner periphery of the outer race -1- equidistant along a circumferential direction. In addition, three stepped holes -8- for bolts used to fix the outer track -1- to an input / output element (not shown) and extending therethrough in an axial direction are also arranged in the outer race of equidistant mode along the circumferential direction. As shown in Figure 1, the cavities -4- and the holes -8- for bolts are arranged alternately and equidistant. In addition, it should be noted that the number of cavities -4- can be selected, for example, between three and six, according to the magnitude of the torque.

As shown in Figure 1, the unidirectional roller-type clutch -30- has accordion springs -5 arranged within the respective cavities -4- and adapted to deflect the rollers -3- towards a coupling direction for the purpose of couple the rollers with the cam surfaces -12-respective.

As shown in Figure 1, one end, that is, a pin -15-, of the accordion spring -5- is fixed to an axial end face -21- of the outer race -1-. In addition, as shown in Figure 5, the other end of the accordion spring -5- is pinched, to form a pin -16-, between an axial end face of the roller -3- and a flange part -17- of a cage -6-. With this arrangement, the spring itself -5- is supported in a fixed state with respect to the outer race -1- and, at the same time, can prevent the roller -3- from being displaced in the axial direction by means of the pin -16 -.

As shown in Figure 8, the accordion spring -5- includes a bellow-shaped part -22- curved in the axial direction of said accordion spring -5-. The bellows part -22- can be expanded and contracted in order to apply a deflection force to the roller -3- in order to couple the roller -3- in this way with the corresponding cam surface -12.

The pin -15- of the accordion spring -5- is fixed to the axial end face -21- of the outer race -1-by welding, spot welding, adhesive, welding alloy or the like. It should be noted that other fixing methods can be used.

Since the accordion spring -5- is fixed to the axial end face -21- of the outer track -1-, the relative position between the accordion spring -5- and the outer track -1- hardly changes or fluctuates . In this way, it is possible to prevent wear and / or breakdown of the accordion spring -5- due to a sliding contact between said accordion spring -5

and a part of the inner diameter of the outer race, a part of the outer diameter of the cage or the guide surface of the inner race.

In addition, since an operation movement of the accordion spring -5- is not influenced by the outer race -1- and the cage -6-, a stable and uniform movement can be achieved. As a result, the coupling capacity of the roller is improved.

(Second embodiment)

Figure 4 is a front view of a unidirectional roller-type clutch, according to a second embodiment of the present invention, and Figure 5 is a front view from a side posterior to that of Figure 4. In addition, Figure 6 is a seen, in axial section, according to the line -BB- in figure 5. In the second embodiment, a cage -6- is arranged on one side of the inner diameter of an outer race -1-.

Figures 4 to 6 show a state in which cam surfaces are coupled to rollers, that is, a locked state in which the unidirectional clutch is coupled under a high load.

As shown in Figures 4 and 5, the unidirectional clutch -30- comprises a cage -6- to contain rollers -3-, and the cage -6- has a cylindrical part -10- and an annular flange part - 17- which extends radially outwards from an axial end of the cylindrical part -10-. In addition, the cage -6- has windows -18- that extend therethrough in a radial direction, and the number of the windows corresponds to the number of the rollers -3-. In this regard, in Figure 5, the flange part -17- is shown partially cut to reveal a cavity -4-.

The window -18- formed in the cylindrical part -10- of the cage -6- extends through said cage in the radial direction, and, in the axial direction, the window is closed both at one end near the part of flange -17- as at one end -19- opposite said flange part -17-. That is, the roller -3- is seated in the substantially rectangular window -18 and is supported by four edges of said window -18-. To show a relationship between the window -18- and the roller -3-, in Figure 1 (also in Figure 4 described below), the highest window -18- is shown in a state in which its end - 19- is trimmed.

Since one axial end of the roller -3- is supported by the pin -16- of the accordion spring -5- and a window edge -18-, and the other axial end is supported by a window edge -18 -, prevents the roller from being dislodged in the axial direction. In this case, if a projection or the like is arranged on the pin -16- to slightly push the axial end face of the roller -3-, said roller -3- is kept in the window -18- more effectively.

As shown in Figures 5 and 6, an annular stepped part -13- is arranged on an axial edge of the inner peripheral surface of the outer race -1- and said stepped part -13- is coupled to the flange part -17 of the cage -6-. The axial depth of the stepped part -13- is slightly greater than the thickness of the flange part -17-, so that, when the stepped part -13- is coupled to the flange part -17-, the end face axial (end face opposite the axial end face -21-) of the outer race -1- becomes flush with the axial end face of the flange part -17-. In addition, the outer diameter of the stepped part -13- is slightly larger than the outer diameter of the flange part -17- of the cage -6-, so that the stepped part -13- is coupled with predetermined play to the flange part -17-.

In this way, since it is not necessary to reduce the axial length of the outer race -1- by a magnitude corresponding to the thickness of the flange part -17-, the axial length of the outer race -1- can be properly maintained, and a coupling margin is left between the cam surface -12- and the roller -3-. In addition, the axial length can be reduced without changing the rigidity of the cam surface -12- of the outer race -1-.

From the resting state shown in Figures 1 to 3, when a load is applied to drive the clutch, the cam surfaces -12- of the cavities -4- are coupled to the rollers -3- deflected by the springs in accordion -5-. In this case, when the rollers -3- are displaced in the circumferential direction, the cage -6- is also displaced together with said rollers -3-. In this way, the windows -18-are also displaced together with the rollers -3-.

In this case, since the axial end face of each roller -3- is supported by the pin -16- of the accordion spring -5- and the other end face is supported by the window -18-, it prevents the roller it is dislodged in the axial direction, thus providing stable operation of said roller.

The corresponding cam surface -12- is coupled to each roller -3- and, at the same time, the outer peripheral surface of the inner race -2-is coupled to a peripheral surface of the roller, which protrudes slightly into the interior of the window -18-. Consequently, the relative rotation between the outer track -1- and the inner track -2- is blocked by the rollers -3-.

As mentioned above, since the cage -6- does not have any means that present rotation to rotate freely, the rollers -3- can move the cage -6-, so that each roller -3- can be moved a certain distance greater than the width of the window -18- of the cage -6-.

As shown in Figures 4 and 6, also in this embodiment, the roller-type unidirectional clutch -30- includes the accordion springs -5- arranged within the respective -4-cavities and adapted to deflect the rollers - 3- towards the direction of coupling, along which the cam surfaces -12- are coupled to said rollers -3-.

Similar to the first embodiment, one end, that is, a pin -15-, of the accordion spring -5- is fixed to the axial end face -21-of the outer race -1-, as shown in Figure 4, and the other end, that is, a pin -16-, is pinched between the axial end face of the roller -3- and the flange part -17- of the cage -6-, as shown in Figure 5. With this arrangement, the accordion spring itself -5- is fixedly supported with respect to the outer race -1- to reduce the fluctuation in the relative position between the outer race -1 and the accordion spring -5- and , at the same time, the pin -16- can prevent the roller -3- from being dislodged in the axial direction.

According to the second embodiment, similar to the first embodiment, since the accordion spring -5- is fixed to the outer race, the relative position between said accordion spring and said outer race does not fluctuate, and thus it is possible prevent wear and / or breakdown of the accordion spring due to the sliding contact between the accordion spring and the inner diameter part of the outer race, the outer diameter part of the cage or the guide surface of the inner race.

In addition, since the operating movement of the accordion spring is not influenced by the outer race and the cage, stable and uniform movement can be achieved. As a result, the coupling capacity of the roller is improved.

Additionally, in addition to the above-mentioned advantages, with the arrangement in which the annular stepped part, with which the flange part of the cage is coupled, is disposed on the axial edge of the inner peripheral surface of the outer race, given Since it is not required to reduce the axial length of the outer race by the magnitude corresponding to the thickness of the flange portion, the axial length of the outer race can be preserved.

In addition, since the rollers and springs can be prevented from being dislodged in the axial and radial directions, said rollers can be effectively coupled even under an environmental condition in which great vibration would be generated, for example, on a motorcycle and Similary.

As shown in Figure 7, since the circumferential width -W- of the window -18- of the cage -6- is smaller than the diameter -R- of the roller -3-, said roller -3- can be seated in the window -18-. As mentioned above, since the cage -6- is not fixed to the outer track -1- and the inner track -2-, said cage can be rotated freely; however, since the roller -3- is adjusted in the window -18-, when said roller -3- is moved inside the cavity -4-, the cage -6- is also rotated accordingly.

Figure 8 is a side view, partial, from one side of the inner diameter of Figure 7. The accordion spring -5 has the pin -15- curved from a bellow-shaped part -20- of the substantially angled body straight and the axial end face of the outer race -1-fits the pin -15-.

In addition, the pin -16- curved from the part -20- of the substantially right angle body is disposed at the end of the spring opposite the pin -15-, the axial end face of the roller -3- being coupled to said pin -16-.

The pin -16-, which is coupled with the roller -3-, is pinched between the axial end face of said roller -3- and the flange part -17- of the cage -6-. Consequently, the pin -16- can retain the roller -3- in the axial direction. Thus, since the accordion spring -5- is maintained in the fixed state, said accordion spring -5 does not fluctuate or moves inside the cavity -4-, thus preventing wear of the accordion spring -5-.

Figures 9 to 11 are front, partial views, to explain an operation of the unidirectional roller-type clutch, in which Figure 9 shows a state in which the inner race -2 is freely rotated, Figure 10 shows a state in which the inner track -2- is displaced from the free rotation to a rotation in the opposite direction, and Figure 11 shows a state in which the inner track -2- is rotated in the opposite direction.

In Figure 9, the inner track -2-is rotated (freely) in the direction shown by the arrow -D-. In this case, when the inner race is rotated -2-, the roller -3- is moved together with the window -18- of the cage -6 towards the accordion spring -5- inside the cavity -4- . That is, since the roller -3- is displaced together with the cage -6- in the rotational direction of the inner race -2-, said roller -3- is shifted to the left in Figure 9, against the deflection force of the accordion spring -5-, while turning in the direction shown by the arrow, as shown.

Figure 10 shows a state in which, before the inner race -2- is rotated in the opposite direction, it

5 decreases the speed of rotation (free rotation) in the direction shown by the arrow, thus decreasing the force to move the roller -3- to the left. In this state, although the roller -3- is displaced towards the cam surface -12- by means of the deflection force of the accordion spring -5-, said roller -3- is not yet coupled with the cam surface -12- .

10 When the inner race -2- begins to rotate in a direction opposite to that of figures 9 and 10 (direction shown by the arrow -E- in figure 11), the load on the roller -3- is eliminated, with the as a result of said roller -3- being moved to a position in which it engages with the cam surface -12-, by means of the deflection force of the spring -5- and the displacement of the window -18- of the cage - 6- displaced due to the rotation in the opposite direction of the inner track -2-. Figure 11 shows this state. In that case, since the roller -3- is

15 displaced together with the cage -6- by the rotation of the inner race -2- to rotate in the direction as shown, said roller -3- engages with the cam surface -12-effectively.

In the high load state for the coupling shown in Figure 11, the rotation of the inner race -2- is transmitted to the outer race -1-by the coupling between the roller -3- and the cam surface -12- . That is, the

20 inner track -2-and outer track -1-are rotated integrally in the direction shown by the arrow.

INDUSTRIAL AVAILABILITY

Although the present invention can be used as a part, such as a pair transmission element of

Forces or a recoil stop in a driving apparatus of a car, an industrial machine or the like, for example, the present invention has excellent effects particularly when used in a motorcycle.

Although the present invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to such exemplary embodiments disclosed. Must be

30 give the scope of the following claims the broadest interpretation to cover all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese patent application number 2008-56210, filed on March 6, 2008.

Claims (7)

1. Unidirectional roller type clutch (30), comprising: 5 an outer track (1) in which cavities (4) are provided with cam surfaces (12) on their inner surfaces; an inner race (2) separated from said outer race (1) on one side of the radial inner diameter and coaxially arranged with said outer race (1) for a relative rotational movement and having an annular outer peripheral guide surface 10 (11) ; a roller (3) disposed within each of said cavities (4) for the purpose of coupling with said cam surfaces (12) and adapted to transmit pairs of forces between said outer track (1) and said inner track (2); Y 15 an accordion spring (5) disposed within each of said cavities (4) and adapted to deflect said rollers (3) in order to engage with said cam surfaces (12), in which one end (15) of each of said accordion springs (5) is fixed to an axial end face (21) of said outer race (1). 2. Unidirectional roller type clutch (30) according to claim 1, wherein each of said springs 20 in accordion (5) is curved in an axial direction. 3. Unidirectional roller type clutch (30) according to claim 1 or 2, wherein said one end (15) of each of said accordion springs (5) is fixed to the axial end face of said outer race (1) by welding. 4. Unidirectional roller type clutch (30) according to claim 3, wherein said one end (15) of each of said accordion springs (5) is fixed to the axial end face of said outer race (1 ) by spot welding. 5. Unidirectional roller type clutch (30) according to claim 1 or 2, wherein said one end (15) of each of said accordion springs (5) is fixed to the axial end face of said raceway exterior (1) by means of an adhesive. 6. Unidirectional roller type clutch (30) according to claim 1 or 2, wherein said one end (15) of 35 each of said accordion springs (5) is fixed to the axial end face of said outer race (1) by welding alloy. 7. Unidirectional roller type clutch (30) according to any one of claims 1 to 6, further comprising a cage (6) that includes a cylindrical part (10) and a radially extending flange part (17) 40 outwards from said cylindrical part (10) and having windows (18) arranged in said cylindrical part (10) and adapted to contain the series of rollers (3), and wherein said flange part (17) which extending radially outwardly is disposed at an axial end of said cylindrical part (10). 8. Unidirectional roller type clutch (30) according to claim 7, wherein a peripheral surface 45 inside said outer race (1) is provided on its axial edge with a stepped part (13) with which said flange part (17) of said cage (6) is coupled.